Description
Starman versions before 0.4019 for Perl allow CPU exhaustion via quadratic regex backtracking when parsing chunked request bodies.

Starman decodes chunked request bodies before calling the application, matching each chunk-size line with `s/^(([0-9a-fA-F]+).*\015\012)//`. A line of hex digits followed by a bare LF and then CRLF never matches, because `.` does not match LF, and each failed attempt backtracks in time quadratic in the length of the hex run. Nothing limits the length of the line.

A remote attacker can exhaust worker CPU by sending such requests to any route.
Published: 2026-10-25
Score: 7.5 High
EPSS: < 1% Very Low
KEV: No
AI Analysis

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Remediation

Vendor Solution

Upgrade to Starman 0.4019 or later.

Tracking

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Advisories

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History

Mon, 02 Nov 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Sun, 25 Oct 2026 23:00:00 +0000

Type Values Removed Values Added
First Time appeared Miyagawa
Miyagawa starman
Vendors & Products Miyagawa
Miyagawa starman

Sun, 25 Oct 2026 17:15:00 +0000

Type Values Removed Values Added
Description Starman versions before 0.4019 for Perl allow CPU exhaustion via quadratic regex backtracking when parsing chunked request bodies. Starman decodes chunked request bodies before calling the application, matching each chunk-size line with `s/^(([0-9a-fA-F]+).*\015\012)//`. A line of hex digits followed by a bare LF and then CRLF never matches, because `.` does not match LF, and each failed attempt backtracks in time quadratic in the length of the hex run. Nothing limits the length of the line. A remote attacker can exhaust worker CPU by sending such requests to any route.
Title Starman versions before 0.4019 for Perl allow CPU exhaustion via quadratic regex backtracking when parsing chunked request bodies
Weaknesses CWE-1333
References

Subscriptions

Miyagawa Starman
cve-icon MITRE

Status: PUBLISHED

Assigner: CPANSec

Published:

Updated: 2026-11-02T14:19:20.636Z

Reserved: 2026-10-23T16:47:20.192Z

Link: CVE-2026-115822

cve-icon Vulnrichment

Updated: 2026-11-02T14:18:53.005Z

cve-icon NVD

Status : Deferred

Published: 2026-10-25T17:17:01.637

Modified: 2026-11-02T15:17:15.440

Link: CVE-2026-115822

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-11-02T17:00:11Z

Weaknesses
  • CWE-1333

    Inefficient Regular Expression Complexity